In his letter he wrote: “As a victim of Che Guevara’s atrocities, as a historian, and as a Cuban of Irish descent, I am deeply disturbed by the fact that the city of Galway is planning to erect a monument to Ernesto Che Guevara.

“I don’t mind one bit if those behind this monstrous project want to believe lies - that’s their right in a truly free society - but it would be wrong to allow their abysmal ignorance or willful blindness to stand unchallenged.

“Those who think highly of Che may be surprised to hear it, but they have way too much in common with Holocaust deniers.

“Che was my neighbor in Havana, and I actually saw him in the flesh several times. He lived in an opulent mansion just a few blocks from my very small house, and also ran the prison of La Cabaña, where some of my relatives ended up being tortured and murdered.

“Their crime? Voicing an opinion different from Che’s. Or, in the case of my uncle, simply having a son who voiced an opinion contrary to Che’s.

“The awful truth about Ernesto Che Guevara is that he was a violent thug with despotic tendencies. Che’s admirers prefer to think of him as a righteous warrior, and often cite certain books that portray him as a saint.

“I hate to break the news to them: Some books are full of lies. Fortunately, others are not, like the memoir Cuba 1959, La Galera de la Muerte, written by Javier Arzuaga, the priest who accompanied all of Che’s victims to the firing squad during the first nine months of the so-called Revolution.

“Read it and weep, please, all of you who love Che.”

Professor Eire also makes an impassioned plea on behalf of his countrymen to the decision makers in Galway.

He added: “We Cubans are the only people on earth who knew the real Che - as opposed to the icon stamped on all sorts of merchandise - but there are many in the world who tune us out, discredit our testimony, and would love to gag us. Somehow, the lie is preferable.

“Why? Ignorance and blind faith. To praise Che, one must overlook mountains of evidence concerning his crimes. But why would anyone do that, willingly?

“Because some people - especially those who see all of history as nothing but class struggle - need a saint to venerate, someone who they think embodies the cause of the downtrodden. “Ironically, though most Che lovers tend not to admit it, they act very much like religious zealots: As they prefer to see it, Che was a saintly crusader for the poor, so everything he did must have been good, and anyone harmed by him must have deserved it.

“So what if he killed Cubans willy-nilly, without trials, including plenty of poor peasants? Or helped establish one of the most repressive regimes on earth?

“Or built concentration camps for dissidents and gays, including one with a sign over the front gate that read ‘Work will make real men out of you?’

“It’s what needed to be done. It was just. And in this warped religious view of Che the idol, and of politics in general, we who call that false history into question are worse than heretics.

“We are the unjust cretins who still deserve to be killed by the likes of Che.”

Eire also likened Guevara to Oliver Cromwell, scoure of the Irish, in his letter.

He said: “Everyone in Galway and Ireland should know this: Che has a lot in common with Oliver Cromwell.

“Like Cromwell, Che proclaimed himself a liberator and felt justified in committing thousands of atrocities in a land other than his own, all in the name of a higher cause.

“Like Cromwell, Che stole everyone’s property too, for a sacred purpose. As for reputation: Cromwell received plenty of good press and adulation from those on his side, just like Che.

“To Cromwell’s admirers - and he had plenty who would eagerly build him monuments - the Irish people were inconsequential obstacles to a higher goal, or worse, despicable papist wretches who deserved no mercy.